Innumerable types of valves are known in the prior art. These valves are used for varied and sundry purposes. One typical use of a valve is to regulate fluid flow through a conduit.
Typical types of valves used to control fluid flow are butterfly and gate valves. Under certain circumstances, these valves are appropriate and adequately serve their function.
In systems designed for moving air, however, these types of valves frequently are inadequate. In such systems, a valve which has a very small dimension in the direction of intended flow is desirable, and these types of valves generally don't satisfy this requirement.
In response to this technological need, the scientific community has developed the iris-like valve. This valve is thin and controls the volume of fluid flow by allowing an aperture to be selectively enlarged or made smaller. The iris-like valve, however, has other drawbacks. It tends to be rather delicate, and its use is limited by the pressure of the environment under which it is to operate. Additionally, even when it is to be used within acceptable pressure parameters, it is mechanically complex and affords numerous opportunities for malfunction.
Attempts have been made to provide butterfly and ball valves which have a limited dimension in the direction of intended flow of the fluid. Even when efforts have been successful in limiting this dimension, these types of valves have proved inadequate for use in air moving systems since, because of the structural configuration of the components within the fluid flow path, distortion of fluid flow inevitably occurs.
It is to these shortcomings in the prior art that the valve of the present application is directed. It provides a structure which not only has a small dimension in the intended direction of fluid flow, but it also affords strength to resist pressures higher than do iris-like valves. Additionally, the interposition of the valve of the present application in a fluid flow conduit does not distort the flow pattern.